avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/arch/nios2/cpu/traps.c

@@ -0,0 +1,26 @@
+/*
+ * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
+ * Scott McNutt <smcnutt@psyent.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <asm/ptrace.h>
+#include <common.h>
+
+void trap_handler (struct pt_regs *regs)
+{
+	/* Just issue warning */
+	printf ("\n\n*** WARNING: unimplemented trap @ %08x\n\n",
+			regs->reg[29] - 4);
+}
+
+void soft_emulation (struct pt_regs *regs)
+{
+	/* TODO: Software emulation of mul/div etc. Until this is
+	 * implemented, generate warning and hang.
+	 */
+	printf ("\n\n*** ERROR: unimplemented instruction @ %08x\n",
+			regs->reg[29] - 4);
+	hang ();
+}